Filter system



c. R. HANNA 1,985,030

FILTER SYSTEM Dec. 18, 19-34.

Filed Match 24, 1931 t Z Z llmmlllllllllllllllll Hlllllllllllmmll I [IIIHIIMWHIHHHIH \umm INVENTOR' ATTORNEY Clinton R-hanvm.

5 ing application Serial No.

Patented Dec. 18,1934

PATENT oFF cE 1,985,030 FILTER SYSTEM Clinton R.- Hanna, Pittsburgh, Pa.,

assignor to Westinghouse Electric & Manufacturing Company, a corporation 0 Application March 24,

3 Claims.

My invention relates to web-handling apparatus and has particular relation to web-tensioning devices.

The present application relates to my copend- 663,377 filed March 29, 1933, which is a division thereof.

It is an object of my invention to provide a web-tensioning device, the action of whch shall be dependent upon the property of elasticity of materials.

Another object of my invention is to provide a web-tensioning device, the action of which shall notbe dependent upon frictional forces.

A further object of my invention is to provide a shoeless web-tensioning device.

A still further object of my invention is to provide, for web-handling apparatus of the type including a web-supporting surface and a plurality of web-advancing elements, a device for insuring that the web shall firmly and uniformly engage the surface. j

- Still another objectof my invention is to provide web-handling; apparatus of a type wherein the web shall be engaged with frictional members on one of its surfaces only.

A still further object of my invention is to provide web-tensioning apparatus of a type wherein the frictional forces, exerted on the web by the web-handling mechanisms, shall be a minimum. More concisely stated, it is an object of my invention to provide web-handling apparatus of a-type incorporating web-tensioning means,- the action of which shall not be dependent upon the frictional forces exerted on the web, and a method for tln'eading the web into the apparatus in such .rnanner as to renden the web-tensioning means effective.

According to my invention, 1 provide a web-- nsioning device comprising a plurality of webadvancing mechanisms that are resiliently driven. Before the web is threaded into the apparatus, the resilient mountings of the web-tensio'ning mechanisms are so stressed that their restoring forces exert a force of tension on the web when it is engaged'by the mechanisms. 9 j

In the specific embodiment of my invention that will be described herein,.the web-handlingapparatus takes the form of a soundrecording system. In this case, theweb is a film. The film is advanced, by a resiliently mounted sprocket wheel, into a regionwhere it passes over a filmul porting roller. It is advanced out of the re gion by a second sprocket wheel that is also resiliently mounted.

The-resiliently mounted sprocket wheels and 1' Pennsylvania 1931, Serial No. 524,879 (Cl. 271-23) sprocket wheels are twisted in such manner that the restoring forces of their resilient mountings are in an outward direction relative to their line of centers. r i

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its'organization and its method of operation, together with additional objects and advantages thereof, will best be understood from thefollowing description of read in connection a specific embodiment, when with the accompanying drawing, in which Figure 1 is a view, in front elevation, showing the essential elements of a sound-recording device constructed according to my invention;

Fig. 2 is a view, in section, taken along the line II'II of Fig. 1, with the elements that are ,unnecessary for purposes of explanation omitted. and a Fig. 3 is a view, partly inperspective and partly in section, showing a sprocket 'wheel and a Pertion-of its shaft of the type utilized in the practice of my invention.

o The apparatus shown in the drawing com-,

prises a film-feeding roller 1 whereby a film 3 is fed from a reel, or froma camera (not shown), as the case may be, into a loop reservoir 5. The film 3 is then advanced by a resiliently mounted sprocket wheel 7 and passes over a film-supportface to the light beam from a sound-recording optical system 11.

After passing over the film-supporting roller 9, the film 3 is engaged by an inertial roller 13 and is advanced into a second loop reservoir 15 by asecond resiliently mounted sprocket wheel 17. By the .term inertialroller I mean a roller having a large. moment of inertia in comparison with the moments of inertia of the other elements of the system.

From the loop reservoir 15, the film is advanced by a sprocket wheel 19 to a take-up reel or to a photographic camera (not shown), depending upon the particular structure of the apparatus with which my improved web-tensioning device is associated.

The resiliently mounted web-advancing meching roller 9 whereon it presents a uniform surprovided for them.

'2 v 1,ass, oso 1 anisms '1 and 1'1 are illustrated in detail in Fig. 2. The rollers '1 and 1'1 are co-axially supported on a plurality of driven shafts 21 and 23 and may be driven, in any well known manner, frompa prime mover (not shown).

The fllm advancing m chanism '1 and 1'1 are rotatable relative to the driving shafts 21 and shafts by springs 25 and 2'1 that are, on the one hand, engaged by pins 29 and 31 secured to the shafts 21 and 23, and, on the other hand, are engaged by pins 33 and 35 secured to the sprocket wheels '1 and 1'1.

The sprocket wheels '1 and 1'1 are furthermore, equipped with suitable slots 3'1 and 39 whereby they are rendered capable of rotating relative to the pins 29 and 31 secured to the shafts 21 and 23.

To prevent the sprocket wheels from oscillating in their natural period, damping devices are I The damping devices comprise washers 41 and 43 ofsuitable damping material, such as felt, preferably lubricated, which are compressed between the" sprocket wheels '1 and 11, and metallic washers 45 and 4'1 secured to the shafts 21 and 23 by springs 49 and 51 to engage'bearings 53 and 55, in which the sprocketwh'eel shafts are rotated, and the endsurfaces of the sprocket wheels.

When being threaded into the apparatus, the film is engaged with one of the sprocket wheels Before the him is engaged sprocket wheel, the one or with the second the other of the after the film is engaged with both sprocket wheels, it is tensioned by the restoring forces The sprocket wheel '1 that feeds the film 3 into the region wherein the sound is impressed thereon is twisted in a counter-clockwise direction, and; the sprocket wheel 1'1 that feeds the film out of this region is twisted in a clockwise direction. When the film is threaded upon thesprocket wheels '1 and 1'1 and over the rollers 9 and 13 in the region, it is, therefore, in a state of tension by reason of the restoring forces exerted thereon by the resilient members 25 and 2'1, whereby the-sprocket wheels are coupled to the shafts 21 and 23.

The resilient couplings 25 and 2'1 of the sprocket wheels '1 and 1'1 enable the latter to adjust their relative movements to the motion of the film 3. The small variations in the angle of twist in th couplings, induced by irre rities in the condition of the film strip, do not effect a marked change in the condition of tension of the film, and it continues to move, under tension, through the apparatus, pr ting a smooth and" uniformly advancing surface to the light beam from the 23. However, they are resiliently coupled to the.

'1 or 1'1 and is brought adjacent to the other.-

optical system. The resilient couplings also prevent the irregularities of the driving system from appearing in the motion of the film. It will be notedthat the combination of the inertial roller 13 and the resiliently mounted sprocket wheels '1 and 17 comprises a mac for a web.

It will be noted that, in the specific embodiment of my invention shown herein, the film-supporting surface 9 is represented as a rotating drum. It may, of course, also be a skid. Fur- 'thermore, it is well'to note that it lies within the scope of my invention to combine the'fllm-supporting roller and the inertial roller into a single member. At times, however, this condition may be undesirable in view of the structure of theapparatus and, in particular, in'view of the fact that it may be desirable to utilize a dink-supporting roller of comparatively large diameter, whereas the inertial roller should be of comparatively small diameter in order to be effective. v I

Moreover, I may point out that, in apparatus including an optical system having a comparatively small angular aperture, and also in apparatus wherein a' highly accurate disposition of the surface of the web presented to the optical system, is not required, the web-supporting surface need not be included.

Finally, it is well to add that devices for latching the sprocket wheels in a tensioned condition during the threading operation may be provided by one skilled in the art. Film-tensioning apparatus, wherein these latching devices are included, are within the scope of my invention.

Although I have shown and described certain specific embodiments of my invention, 1 am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted, except insofar as is necessitated by the prior art and by the spirit of the appended claims. 1 l

I claim as my invention: i

1. Web-tensioning apparatus comprising webadvancing means, means for resiliently driving said web-advancing means, and frictional damping means for said web-advancing means.

2. Web-tensioning apparatus comprising webadvancing means, means for resiliently driving said web-advancing means, means for frictionally means driven by said web.

nioal filtering system I damping said web-advancing means, and inertial 3. In a motion-picture apparatus, film-driving apparatus including film-supporting means, fllmadvancing means, means for resiliently driving said film-advancing means, and frictional damp-- ing means for said film-advancing means.

- CLINT N R. HANNA. 

